The design of water closets (WCs) in Australia has been greatly influenced by the need to minimise water consumption and maintain adequate sanitation systems to safeguard and maintain a high level of public health. Since 1982, reductions in Australian WC flushing volumes have led to a major lowering of the average daily WC water consumption per person from 55 liters to 16.5 liters.
A major contribution to this reduction was the development of the two button dual flush WC having 6/3 liter reduced flush technology which gave the user the choice of applying either a 6 liter full flush or a 3 liter reduced flush option to operate the WC. More recently, toilets which give the user the choice of applying either a 4.5 liter full flush or a 3 liter reduced flush option have been developed.
Known attempts known to operate toilets with flushing volumes approaching the ultra low flushing volumes referred to above have led to difficulty in transporting solids waste through sewer drainlines.
Further, known devices developed to address these drainline problems have been large, complicated and expensive, and often required installation under the floor on which the toilet is installed. Such installations are not possible due to budgetary and/or space limitations in many buildings.